Abstract: Implantable medical systems enter an exposure mode of operation, either manually via a down linked programming instruction or by automatic detection by the implantable system of exposure to a magnetic disturbance. A controller then determines the appropriate exposure mode by considering various pieces of information including the device type including whether the device has defibrillation capability, pre-exposure mode of therapy including which chambers have been paced, and pre-exposure cardiac activity that is either intrinsic or paced rates. Additional considerations may include determining whether a sensed rate during the exposure mode is physiologic or artificially produced by the magnetic disturbance. When the sensed rate is physiologic, then the controller uses the sensed rate to trigger pacing and otherwise uses asynchronous pacing at a fixed rate.

Abstract: Implantable medical systems enter an exposure mode of operation, either manually via a down linked programming instruction or by automatic detection by the implantable system of exposure to a magnetic disturbance. A controller then determines the appropriate exposure mode by considering various pieces of information including the device type including whether the device has defibrillation capability, pre-exposure mode of therapy including which chambers have been paced, and pre-exposure cardiac activity that is either intrinsic or paced rates. Additional considerations may include determining whether a sensed rate during the exposure mode is physiologic or artificially produced by the magnetic disturbance. When the sensed rate is physiologic, then the controller uses the sensed rate to trigger pacing and otherwise uses asynchronous pacing at a fixed rate.

Abstract: An implantable medical device (IMD) automatically determines at least a portion of the parameters and, in some instances all of the parameters, of an exposure operating mode based on stored information regarding sensed physiological events or therapy provided over a predetermined period of time. The IMD may configure itself to operate in accordance with the automatically determined parameters of the exposure operating mode in response to detecting a disruptive energy field. Alternatively, the IMD may provide the automatically determined parameters of the exposure operating mode to a physician as suggested or recommended parameters for the exposure operating mode. In other instances, the automatically determined parameters may be compared to parameters received manually via telemetry and, if differences exist or occur, a physician or patient may be notified and/or the manual parameters may be overridden by the automatically determined parameters.

Abstract: An implantable medical device (IMD) configures one or more operating parameters of the IMD based on a type of source of a disruptive energy field to which the IMD is exposed. The disruptive energy field may, in one example, include magnetic and/or radio frequency (RF) fields generated by an MRI scanner. In one aspect, the IMD may distinguish between different types of MRI scanners and select an exposure operating mode tailored to reduce the effects of the particular type of MRI scanner. In another aspect, the IMD may adjust one or more operating parameters that will be used when the IMD returns to a normal operating mode after exposure to the MRI scanner based on the type of MRI scanner to which the IMD is exposed.

Abstract: An implantable medical device (IMD) automatically determines at least a portion of the parameters and, in some instances all of the parameters, of an exposure operating mode based on stored information regarding sensed physiological events or therapy provided over a predetermined period of time. The IMD may configure itself to operate in accordance with the automatically determined parameters of the exposure operating mode in response to detecting a disruptive energy field. Alternatively, the IMD may provide the automatically determined parameters of the exposure operating mode to a physician as suggested or recommended parameters for the exposure operating mode. In other instances, the automatically determined parameters may be compared to parameters received manually via telemetry and, if differences exist or occur, a physician or patient may be notified and/or the manual parameters may be overridden by the automatically determined parameters.

Abstract: This disclosure describes techniques for configuring an IMD into the exposure operating mode. Prior to a medical procedure that generates a disruptive energy field, such as an MRI scan, an electronic prescription is configured to indicate that the IMD is authorized for the medical procedure that includes a disruptive energy field. The electronic prescription includes one or more designated bits within a storage element of the IMD. When the patient in which the IMD is implanted arrives for the medical procedure, a user (such as an MRI operator) interacts with a telemetry device to determine whether the electronic prescription is configured. Upon determining that the electronic prescription is configured, the IMD transitions into the exposure operating mode designed for operation in the disruptive energy field. In this manner, the electronic prescription confirms to the user that that the IMD has been checked for suitability for operation during the medical procedure.

Abstract: An IMD may transition to an MRI mode automatically in response to detecting one or more conditions indicative of the presence of a strong magnetic field. Large static magnetic fields, such as those produced by an MRI device, may interact with the blood of a patient as it flows through the magnetic field to produce a voltage, a phenomenon referred to as the magnetohydrodynamic (MHD) effect. The voltage produced by the MHD effect is proportional to the strength of the magnetic field. As such, the voltage produced by blood flow in the strong magnetic field of an MRI device may result in a change in a characteristic of an electrogram (EGM). The IMD may detect the change in the characteristic of the EGM caused by the MHD effect and transition to operation in the MRI mode in response to at least the change in the EGM.

Abstract: An IMD may transition to an MRI mode automatically in response to detecting one or more conditions indicative of the presence of a strong magnetic field. Large static magnetic fields, such as those produced by an MRI device, may interact with the blood of a patient as it flows through the magnetic field to produce a voltage, a phenomenon referred to as the magnetohydrodynamic (MHD) effect. The voltage produced by the MHD effect is proportional to the strength of the magnetic field. As such, the voltage produced by blood flow in the strong magnetic field of an MRI device may result in a change in a characteristic of an electrogram (EGM). The IMD may detect the change in the characteristic of the EGM caused by the MHD effect and transition to operation in the MRI mode in response to at least the change in the EGM.

Abstract: This disclosure provides a pacing technique that reduces the effect of oversensing caused by noise on pacing therapy. The IMD delivers a pacing pulse subsequent to sensing an electrical signal on the lead when the sensed electrical signal coincides with an independently detected noise signal and the sensed electrical signal occurs during a period of time of an expected intrinsic cardiac signal. The IMD may, in some instances, trigger delivery of the pacing pulse during the escape interval instead of waiting for the escape interval to expire. Pacing in accordance with the techniques of this disclosure may allow for improved therapy during an MRI procedure by decreasing the risk associated with inappropriate pacing inhibition as well as decreasing the risk associated with pacing during the vulnerable period of the cardiac cycle.

Abstract: An implantable medical system includes an implantable medical lead including at least one electrode and an implantable medical device (IMD) coupled to the implantable medical lead. The IMD includes a sensing module that obtains electrical signals on the implantable medical lead. The electrical signals on the implantable medical lead include cardiac signals as well as noise-induced signals. The IMD also includes a noise detection module that obtains noise signals independently of the electrical signals on the implantable medical lead. A control module of the IMD adjusts a sensing threshold of the sensing module in response to detecting the noise signals via the noise detection module. In instances in which the amplitude of the noise-induced signal on the lead is too large, the IMD may transition to a noise operating mode specifically designed to accommodate noisy environments.

Abstract: This disclosure provides a pacing technique that reduces the effect of oversensing caused by noise on pacing therapy. The IMD delivers a pacing pulse subsequent to sensing an electrical signal on the lead when the sensed electrical signal coincides with an independently detected noise signal and the sensed electrical signal occurs during a period of time of an expected intrinsic cardiac signal. The IMD may, in some instances, trigger delivery of the pacing pulse during the escape interval instead of waiting for the escape interval to expire. Pacing in accordance with the techniques of this disclosure may allow for improved therapy during an MRI procedure by decreasing the risk associated with inappropriate pacing inhibition as well as decreasing the risk associated with pacing during the vulnerable period of the cardiac cycle.

Abstract: An IMD may transition to an MRI mode automatically in response to detecting one or more conditions indicative of the presence of a strong magnetic field. Large static magnetic fields, such as those produced by an MRI device, may interact with the blood of a patient as it flows through the magnetic field to produce a voltage, a phenomenon referred to as the magnetohydrodynamic (MHD) effect. The voltage produced by the MHD effect is proportional to the strength of the magnetic field. As such, the voltage produced by blood flow in the strong magnetic field of an MRI device may result in a change in a characteristic of an electrogram (EGM). The IMD may detect the change in the characteristic of the EGM caused by the MHD effect and transition to operation in the MRI mode in response to at least the change in the EGM.

Abstract: An IMD may transition to an MRI mode automatically in response to detecting one or more conditions indicative of the presence of a strong magnetic field. Large static magnetic fields, such as those produced by an MRI device, may interact with the blood of a patient as it flows through the magnetic field to produce a voltage, a phenomenon referred to as the magnetohydrodynamic (MHD) effect. The voltage produced by the MHD effect is proportional to the strength of the magnetic field. As such, the voltage produced by blood flow in the strong magnetic field of an MRI device may result in a change in a characteristic of an electrogram (EGM). The IMD may detect the change in the characteristic of the EGM caused by the MHD effect and transition to operation in the MRI mode in response to at least the change in the EGM.

Abstract: An IMD is selectively configurable to support a plurality of programming options for enabling and disabling an exposure operating mode of the device. In one example, the IMD may support at least two of a manual exposure mode programming option in which the exposure operating mode is manually enabled and manually disabled, an automatic exposure mode programming option in which the exposure operating mode is automatically enabled and automatically disabled, or a semi-automatic exposure mode programming option in which the exposure operating mode is either automatically enabled and manually disabled or manually enabled and automatically disabled. In this manner, the IMD may support more than one way for enabling and disabling the exposure operating mode to provide flexibility in the clinical workflows associated with programming the IMD into an exposure operating mode for a medical procedure, such as an MRI scan.

Abstract: An IMD is selectively configurable to support a plurality of programming options for enabling and disabling an exposure operating mode of the device. In one example, the IMD may support at least two of a manual exposure mode programming option in which the exposure operating mode is manually enabled and manually disabled, an automatic exposure mode programming option in which the exposure operating mode is automatically enabled and automatically disabled, or a semi-automatic exposure mode programming option in which the exposure operating mode is either automatically enabled and manually disabled or manually enabled and automatically disabled. In this manner, the IMD may support more than one way for enabling and disabling the exposure operating mode to provide flexibility in the clinical workflows associated with programming the IMD into an exposure operating mode for a medical procedure, such as an MRI scan.

Abstract: This disclosure describes techniques for configuring an IMD into the exposure operating mode. Prior to a medical procedure that generates a disruptive energy field, such as an MRI scan, an electronic prescription is configured to indicate that the IMD is authorized for the medical procedure that includes a disruptive energy field. The electronic prescription includes one or more designated bits within a storage element of the IMD. When the patient in which the IMD is implanted arrives for the medical procedure, a user (such as an MRI operator) interacts with a telemetry device to determine whether the electronic prescription is configured. Upon determining that the electronic prescription is configured, the IMD transitions into the exposure operating mode designed for operation in the disruptive energy field. In this manner, the electronic prescription confirms to the user that that the IMD has been checked for suitability for operation during the medical procedure.

Abstract: This disclosure describes techniques for configuring an IMD into the exposure operating mode. Prior to a medical procedure that generates a disruptive energy field, such as an MRI scan, an electronic prescription is configured to indicate that the IMD is authorized for the medical procedure that includes a disruptive energy field. The electronic prescription includes one or more designated bits within a storage element of the IMD. When the patient in which the IMD is implanted arrives for the medical procedure, a user (such as an MRI operator) interacts with a telemetry device to determine whether the electronic prescription is configured. Upon determining that the electronic prescription is configured, the IMD transitions into the exposure operating mode designed for operation in the disruptive energy field. In this manner, the electronic prescription confirms to the user that that the IMD has been checked for suitability for operation during the medical procedure.

Abstract: An implantable medical device (IMD) determines an effect of the disruptive energy field and adjusts one or more operating parameters of the IMD based on at least the determined effect. In some instances, the IMD may determine an actual effect of the disruptive energy field, such as a temperature change, impedance change, pacing or sensing threshold change, MRI-induced interference one pacing or sensing, or other actual effect. In other instances, the IMD may determine a predicted effect of the disruptive energy field based on one or more characteristics of the exposure. In any case, the IMD adjusts one or more parameters based on at least the determined effect.

Abstract: An implantable medical device (IMD) configures one or more operating parameters of the IMD based on a type of source of a disruptive energy field to which the IMD is exposed. The disruptive energy field may, in one example, include magnetic and/or radio frequency (RF) fields generated by an MRI scanner. In one aspect, the IMD may distinguish between different types of MRI scanners and select an exposure operating mode tailored to reduce the effects of the particular type of MRI scanner. In another aspect, the IMD may adjust one or more operating parameters that will be used when the IMD returns to a normal operating mode after exposure to the MRI scanner based on the type of MRI scanner to which the IMD is exposed.

Abstract: An implantable medical device (IMD) configures one or more operating parameters of the IMD based on a type of source of a disruptive energy field to which the IMD is exposed. The disruptive energy field may, in one example, include magnetic and/or radio frequency (RF) fields generated by an MRI scanner. In one aspect, the IMD may distinguish between different types of MRI scanners and select an exposure operating mode tailored to reduce the effects of the particular type of MRI scanner. In another aspect, the IMD may adjust one or more operating parameters that will be used when the IMD returns to a normal operating mode after exposure to the MRI scanner based on the type of MRI scanner to which the IMD is exposed.